Apparatus for charging and discharging concrete materials



March 6, 1951 G. HILKEMEIER 2,544,085

APPARATUS FOR CHARGING AND DISCHARGING CONCRETE MATERIALS Filed Jan. 29,1948 2 Sheets-Sheet 1 LOUIS G. HILKEMEIER INVENTOR AT TORNE Y March 6,1951 2 Sheets-Sheet 2 Am HU V /3.9 I l uh. L.G.H|LKEME|ER v x I I lllllINVENTOR /Z3 l MIHIII ATTORNEY Patented Mar. 6, 1951 UNITED STATESPATENT OFFICE 5. C aim i This invention relates to. concrete. mixers;and: in particular to the. mounting. for the. charging. hoppersusedtherewith and has matterdescribed. herein which isdisclosed andclaimed in the.co.-..

pending-.- application of Roy M. Hawkins, entitled Apparatus for-Charging and Discharging Con-=.

crete Mixers, filed December 2'1 1947, Serial. No. 794150, and theapplication of Louis G. Hilkemeierand Roy M, Hawkins, entitled Apparatusfor Charging and Discharging Concrete Mixers, filed January 12, 1948,SerialNo. 1,743.

In truck mounted concrete mixers it is now widespreadpractice tomountthe mixing drum on an axis which is inclined as regardsto thehorizontal. Associated with such mounted mixers is a charging hopper, anexample of such a hopper is shown in the Letters Patent issued to R. J.Barnes on May 1, 1945-, 2,374,912. The use of such apparatus has agreat; advantage in that it enables thechar-g-ing and-discharging of themixing drum contents through a single opening. However, since; themass-of concrete. is an abrasive substance any apparatus used therewithmust necessarilybe subject to abrasive wear. Inthe aforesaid LettersPatent to R. J. Barnes a charging hopper mounting for truck typeconcrete mixers is disclosed which'has-some advantages over the priorart. Nevertheless suchstructure has been found to have inherent failingswhich necessitated costly repair and replacement after comparativelyshort periods of use. This is by reason of thefact that a rotatableclosure ring is journalled on a; nonrotatable hopper; a seal is providedand also thrust accommodating means. The structure of-the said thrustaccommodating means when viewedwiththe mounting apparatus as a whole wassuch as to wear very rapidly especially when abrasive substancesbeoamelodged therewith. For; all of the forcenecessary to bring therotatable closure ring into sealing engagement with the drumis exertedthrough the. thrust assembly, hence the thrust accommodatingmeans-quickly wore out. Such a condition usually requires expensive.repair or replacementof thehopper apparatus and results in muchlost-time.

Accordingly, it is an object of: this invention to.

provide pivotally mounted charging; hoppersfor concrete mixers with.means necessary. to seal the.

mouth of thedrum opening,- which exert the necessary force through therotatable closure ring instead of through-the-entire hopper assembly.

The foregoing is necessarily the broad object of this invention, howeverother objectswil'lappear to those skilled inthe. art inthereading of thefollowing description and claims.

In the figures, Fig. 1 represents a front elevation'- partlybroken away,of a: charging hopper mounted on an inclined axistruckmixerl Fig. 2-isasideelevationpartly broken away; of theihopper-mounting.

Fig. 3 is an enlarged view, partly in section, of the: apparatus shownin Fig. 2.

Referring to, the figures, Fig. 1 shows a mixing drum H2 of the inclinedaxistype mounted to the frame H! of theconventional type, truck mixer.Pivotally mounted to said frame is the hopper I H] which directsmaterials into the drum during the charging operation. i-he hopper andclosure ring function accordingly, when the hopper is pivoted about theshaft 12'! the rotatable closure ring I23 is free of the mouth H3 of themixing drum and thecontents can be discharged therefrom, when the hopperis again brought into engagement with the mouth of the mixing drum the.rotatable closure ring I23 seats itself on the mouth of the mixing drum,sealing the same. The hopper is in this position during most of the timethat the truck mixer is in operation, as charging and dischargingoperations are relatively infrequent during normal operations.

The hopper is supported by, means of the arms I253 which are pivotallyconnected to the rock shaft I21. These arms are not keyed to said shaftbut are free to rock thereabout. They are flex ibly mounted to thenonrotatable hopper by means of deformable or rubber-like bushings Hi5which engage a bushing I46, said bushing registering with the pin H8which is attached to the hopper llll. Although not shown in thedrawings, it will be appreciated that the aforesaid arm and bushingstructure is duplicated on the opposite side of the hopper, a pinsimilar to pin H8 being in alignment with pin H8 with their axesapproximately intersecting an extension of the drum axes. A resilientconnection 528 is provided between the hopper Hi3 and the arm lift andis so arranged so that the hopper will not tip when it is in a raisedposition. In this manner a resilient support for the hopper mechanism isafforded which may accommodate the erratic movements of the drumopeningas respects to the frame of the mixer when the truck mixertravels over rough terrain, such travel occasioning weaving andtwistingof the frame.

The hopper is moved from a dischargeposition to a charging position bypivoting the same about the shaft I21. This'is accomplished by havingarms I M keyed to said shaft: a lever 526 is likewise keyed to saidshaft and a rodmember 125 is attached to said lever; the rod I25 may bemoved by means of any conventional bell and crank mechanism by themanipulation of an operator. The levers I have a lost motion connectionI50 which cooperates with an enlarged portion of the pin I I8, thisarrangement moves the hopper toward and away from the mouth. of the drumopening when theshaft l2l'is rocked in the corresponding direction.

Fig. 3 shows the rotatable closure ring I23, the hopper ID. and the.connecting means between themwhich includesa sea-l Miand' athrust plateI42 which is an annular member integral with the closure member and isset in the groove I4I of the hopper III]. In the prior art all of theforce required to bring the rotatable closure ring I23 into sealingengagement with the mouth of the mixing drum H3 was exerted through andupon the thrust ring I42 as shown in the aforesaid Barne patent. Thisforce is necessarily great and brought about the condition in a shorttime wherein the thrust ring was so badly worn that it had to bereplaced. Also the rotatable closure member I23 was displaced axiallytoward the mouth of the mixing drum so that the seal I44 had noeffectiveness, consequently great expense was entailed to repair thisdeficiency. Fig. 3 shows a track member I22 integral with the rotatableclosure ring I23. A rolling member I39 rides on the track member I22,this rolling member is integral with the lever H4 and is so arranged toexert all the force necessary to bring the rotatable closure ring I23into sealing engagement with the mouth of the mixing drum I I3 throughor directly upon the rotatable closure ring itself. This obviates anyexcessive thrust on the thrust ring I42 as only the weight of the hopperis absorbed by said ring and it is free to .float in the hopper grooveMI.

As the hopper H9 is brought adjacent the :mouth of the mixing drum H3 itmates with the Lfiared opening divided at said mouth and before therotatable closure ring effectively seals the .mouth of the drum theremust be some adjust-' ment of the rotatable closure ring to the axis ofrotation of said month. In the past this sometimes accounted foreccentric movement of the rotatable closure ring as respects to themouth of the drum because the adjustment was not possible, withconsequent strain upon the hopper mounting apparatus. In this embodimentof the invention clearance exists between the lost motion aperture I50and the pin H8 as shown in Figs. 1 and 2. It will also be noted thatthere is lateral clearance between the head of said pin and the leverarm H i, also on the opposite side L there is clearance between thelateral faces of levers H4 and I29. This enables the rotatable closurering and the entire hopper assembly to float before finding itsconoentricity with the mouth of the mixing drum. The roller I39 is shownas the chosen embodiment to urge the closure ring forward, however itcan be appreciated that sliding contact means might otherwise be used.Also, equivalents other than those of the chosen embodiment are notshown but may be selected byone skilled in the art. Hence, the inventionis to be limited only by the clear import of the following claims.

I claim:

1. In a transit concrete mixer, a drum rotatably mounted on an inclinedaxis and having its rear elevated end open; a charging hopper; astationary frame pivotally mounting the charging hopper to swing towardand from the elevated open end of the drum; a sealing member carried bythe charging hopper and engageable in sealing relationship with themouth of said drum when the charging hopper is in its lowered position;means for winging the charging hopper upwardly away from the open end ofthe drum to enable discharge of the drum'contents, said means furthercomprising actuatable lost motion linkage connected to the hopper; meansfor urging said sealing member into sealing relationship with the mouthof said drum, said means being attached 4 to said swinging means andarranged to exert the force necessary to seal the drum through thesealing member.

2. In a concrete mixer, a rotatable mixing drum having an open endthrough which the drum is charged and discharged; a charging hopper; apivotal support for said hopper, a rotatable closure member on saidhopper arranged to seal said open end of the drum when the former isbrought into engagement therewith, means for urging said rotatableclosure member into engagement with the mouth of said drum, said meansincluding movable arms on each side of said drum having lost motionconnections with said hopper and engaging said rotatable closure member,whereby said means perform the dual function of opening and closing themouth of said drum while exerting the force necessary to seal said drumwhen the hopper is in a closed position through the rotatable closuremember.

3. Hopper mounting apparatus for transit concrete mixers wherein thehopper has a rotatable closure ring journaled thereon, comprising freelypivoted arms for supporting said hopper assembly for movement about apivot point, lost motion linkage means for moving said hopper assemblyabout its pivot point, said lost motion linkage further comprisingmovable means abutting a trackwa on the rotatable closure ring forurging the same into sealing engagement with the mouth of an associatedmixing drum, and means for actuating said lost motion linkage to movethe hopper from a discharge position to a charging position and viceversa.

4. In a concrete mixer, a rotatable mixing drum having an open endthrough which the drum is charged and discharged; a charging hopper; apivotal support for said hopper, a rotatable closure member on saidhopper arranged to seal said open end of the drum when the former isbrought into engagement therewith, a trackway on said rotatable closuremember, means for urging said rotatable closure member into engagementwith the mouth of said drum, said means comprising movable arms on eachside of said drum having lost motion connections to said hopper wherebysaid means perform the dual function of opening and closing the mouth ofsaid drum while exerting the force necessary to seal said drum when thehopper is in closed position through the rotatable closure member, saidmovable arms having moving contact members for engagement with saidtrackway on the rotatable closure member during the sealing step.

5. Apparatus according to claim 4 in which the lost motion connection tosaid hopper engages pin-like members disposed substantially on thediameter of said hopper, said lost motion connection to the pin-likemember having lateral and transverse clearance with said pin-likemembers whereby the hopper assembly may float while searching for itsconcentricity with the axis of the mouth of said mixing drum.

LOUIS G. HILKEMEIER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 773,375 Cooper Oct. 25, 1904999,525 Shero Oct. 1, 1911 1,848,223 Reed Mar. 8, 1932 2,374,912 BarnesMay 1, 1945

